[Oxidative stress and hypercholesterolemia: increase of radical hydroxyl in patients with hypercholesterolemia]

A close relationship exists between high blood cholesterol levels and atherosclerosis. This relationship, which represents an important risk factor for cardiovascular diseases, may be dependent on enhanced oxidative stress. To investigate this hypothesis, we studied 20 patients (12 females and 8 males, aged between 40 and 65 years) with high blood cholesterol levels (240-450 mg/dl) but without other risk factors for atherosclerosis and 20 healthy individuals matched for sex and age, with blood cholesterol levels < 240 mg/dl. We elaborated a laboratory technique that identifies two metabolites of the hydroxyl radical, the 2,3 and the 2,5 dihydroxybenzoic acid (DHBA), in basal conditions and after stimulation by 0.5-1 microM formyl-methionine-leucyl-phenylalanine, which is a specific activator of leukocytes. Results show that patients with hypercholesterolemia have a significant increase of 2,3 e 2,5 DHBA both in basal conditions and after stimulation (p = 0.03). A significant correlation (rho = 0.474; p = 0.004) was found between 2,3-2,5 DHBA and serum cholesterol. This study shows that patients with hypercholesterolemia have enhanced leukocyte oxidative stress and suggests that cholesterol could play a pivotal role.